JP6183852B2 - Axial blower - Google Patents

Description

  The present invention relates to an axial blower used for a cooling fan or the like.

  The axial blower includes a casing having an intake port and an exhaust port in a uniaxial direction, and an impeller disposed in the casing. The impeller has a plurality of blades on the outer peripheral portion of the hub, and when these blades rotate, air is sucked from the intake port and discharged from the exhaust port.

6A and 6B are diagrams showing a state of exhaust air discharged from an exhaust port of an axial blower according to a conventional example, where FIG. 6A shows simulation results and FIG. 6B shows measured data.
As shown in this figure, in the conventional axial blower 101, the exhaust air discharged from the exhaust port 102 tends to diffuse outward, and there is a problem that static pressure does not increase. In FIG. 6, 103 is an air inlet, 104 is an impeller, and 105 is a stationary blade.

  In order to solve this problem, an axial blower in which two impellers (a front impeller and a rear impeller) are arranged in series in a single axial direction via a middle stationary portion has been proposed (see, for example, Patent Document 1). According to such an axial blower, the air volume / static pressure characteristics are enhanced by rotating the two impellers in opposite directions.

JP 2011-122570 A

  However, in the counter-rotating axial flow fan that rotates the two impellers in opposite directions, there is a problem that noise increases due to turbulence of airflow flowing from the front impeller to the rear impeller. In order to solve this problem, in the axial blower disclosed in Patent Document 1, a turbulent flow generation projecting surface is provided on the inner peripheral portion of the casing, and noise is suppressed by intentionally generating turbulent flow on the front side of the rear impeller. However, due to the occurrence of turbulent flow, there is a problem that the tendency of the exhaust wind to diffuse increases and the straightness of the exhaust air cannot be obtained.

  The present invention has been made in view of such circumstances, and an axial blower capable of suppressing the occurrence of turbulence and improving the straightness of exhaust air while avoiding an increase in noise and a decrease in static pressure. The purpose is to provide.

In order to achieve such an object, the present invention is grasped by the following configuration.
(1) The axial blower of the present invention has a casing having an inlet and an outlet in a uniaxial direction, a plurality of blades on the outer periphery of the hub, and the hub is disposed in the casing so as to be along the uniaxial direction. The casing has a plurality of protrusions extending toward the exhaust port side on an inner peripheral surface facing the outer end surface of the blade.

(2) In the configuration of (1), the blade has a step portion on the outer end surface facing the base end portion of the protrusion, and the step portion protrudes from the rotation center axis of the impeller. The distance from the rotation center axis of the impeller to the outer end surface that does not face the protruding portion is made longer than the distance to the outer end surface that faces the protruding portion.

(3) In the configuration of (1) or (2) above, the base end portion on the intake port side of the ridge portion is located at the position of the inner peripheral surface of the casing within a range facing the outer end surface of the blade. The ridge portion is provided continuously from the base end portion to the end surface of the casing on the exhaust port side.

(4) In the configurations of (1) to (3) above, the ridge extends so as to move in the rotational direction of the blades toward the exhaust port when viewed from the radial direction.

(5) In the configurations of (1) to (4), the protruding portion protrudes from the inner peripheral surface of the casing toward the intake port side at a base end portion of the casing on the intake port side. It is inclined so that becomes smaller.

  According to the present invention, it is possible to provide an axial blower that can suppress the occurrence of turbulent flow and improve the straightness of exhaust air while avoiding an increase in noise and a decrease in static pressure.

It is a figure which shows the axial blower which concerns on embodiment of this invention, (a) is the side view which abbreviate | omitted a part of casing, (b) is a sectional side view. It is the perspective view which looked at the axial-flow fan which concerns on embodiment of this invention from the exhaust port side. It is a rear view which shows the impeller of the axial-flow fan which concerns on embodiment of this invention. It is a partial sectional view showing typically the shape of an impeller in relation to the ridge part of the axial blower concerning the embodiment of the present invention, and (a) is a case where a step is provided on the outer end face of the impeller blades (B) is the figure which showed the case where the step part is not provided in the outer side end surface of the impeller blade | wing. It is a figure which shows the state of the exhaust air discharged | emitted from the exhaust port of the axial flow fan which concerns on embodiment of this invention, (a) is a simulation result, (b) is measurement data. It is a figure which shows the state of the exhaust wind discharged | emitted from the exhaust port of the axial flow fan which concerns on a prior art example, (a) is a simulation result, (b) is measurement data.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the accompanying drawings.
In the description of the embodiments, the same numbers are assigned to the same elements throughout.

(Overall configuration of axial blower)
First, the whole structure of the axial-flow fan 1 which concerns on embodiment of this invention is demonstrated with reference to FIG.

Drawing 1 is a figure showing an axial blower concerning an embodiment of the present invention, (a) is a side view which omitted some casings, and (b) is a sectional side view.
As shown in FIG. 1A, an axial blower 1 according to an embodiment of the present invention is arranged in a cylindrical casing 10 having an intake port 2 and an exhaust port 3 in a uniaxial direction, and at the center of the intake port 2. A base portion 20, a bearing housing 13 (see FIG. 1 (b)) protruding from the center portion of the base portion 20 toward the exhaust port 3, an outer peripheral portion of the base portion 20, and an inner peripheral portion of the casing 10. A plurality of stationary blades 30 integrally provided between the impeller 40, an impeller 40 disposed on the exhaust port 3 side (hereinafter also referred to as a downstream side) from the stationary blade 30 in the casing 10, and an outer rotor type that rotates the impeller 40. The motor part 70 is provided.

  The impeller 40 includes a bottomed cylindrical hub 41 and a plurality of (for example, three) blades 42 protruding from the outer periphery of the hub 41. The number of blades 42 is not particularly limited, and may be reduced or increased as necessary. As shown in FIG. 1B, a rotor 60 is provided at the inner peripheral portion of the hub 41, and a shaft 44 is provided at the center of the hub 41. The shaft 44 is a bearing via a bearing 13a. The housing 13 is rotatably supported.

  As shown in FIG. 1B, the motor unit 70 includes a stator 50 fixed to the outer peripheral portion of the bearing housing 13 and a rotor disposed on the inner peripheral portion of the hub 41 so as to face the outer peripheral portion of the stator 50. 60. The stator 50 includes a stator core 51 fixed to the outer peripheral portion of the bearing housing 13, an insulator 52 provided in a coil winding portion of the stator core 51, and a plurality of coils 53 wound around the stator core 51 via the insulator 52. The rotor 60 includes a rotor yoke 61 that is integrally provided on the inner side of the hub 41, and a rotor magnet 62 that is mounted on the inner peripheral portion of the rotor yoke 61 side by side in the circumferential direction.

  The outer rotor type motor unit 70 configured as described above supplies the rotor 60 and the impeller 40 integral with the rotor 60 by sequentially supplying current to the plurality of coils 53 at a predetermined timing from a power source unit (not shown). Rotate in a predetermined direction. When the impeller 40 rotates, air is sucked from the intake port 2 and the sucked air is discharged from the exhaust port 3.

  Below, the characteristic structure of the axial-flow fan 1 which concerns on embodiment of this invention is demonstrated with reference to FIGS.

(Case of embodiment)
FIG. 2 is a perspective view of the axial blower according to the embodiment of the present invention as viewed from the exhaust port 3 side.
As shown in FIG. 2, the casing 10 has a plurality of (for example, fifteen) protrusions 11 that extend toward the exhaust port 3 side on the inner peripheral surface facing the outer end surface of the blade 42. According to such a ridge portion 11, since the airflow flowing along the inner peripheral surface of the casing 10 is rectified so as to be directed toward the exhaust port 3, highly straight air is discharged from the exhaust port 3, and is discharged. The spread of the entire wind can be suppressed. In addition, the number of the protrusion parts 11 is not limited to 15, It may increase as needed and may reduce conversely.

  The protrusion 11 is within the range from the end on the intake port 2 side of the outer end surface of the blade 42 to the end surface of the exhaust port 3 of the casing 10 in the inner peripheral surface of the casing 10 (the range shown in FIG. 1A). A) is preferable. More specifically, when viewed in a sectional view in which the inner peripheral surface of the casing 10 is cut in the axial direction, the range in which the blades 42 overlap the inner peripheral surface of the casing 10 in the radial direction, that is, the outer end surfaces of the blades 42. There is a start position (base end position on the intake port 2 side) of the ridge portion 11 at the position of the inner peripheral surface of the casing 10 within the facing range, and the ridge portion 11 is provided from there toward the exhaust port 3 side. It is done.

In other words, the protrusion 11 is provided continuously on the inner peripheral surface of the casing 10 with the middle portion of the intake port 2 and the exhaust port 3 as the base end position and the end surface on the exhaust port 3 side. In the vicinity (base end portion) of a certain range from the base end position of the protrusion 11, an inclined surface (see the protrusion 11 shown in FIG. 4A) is provided. However, the base end portion does not necessarily have the inclined surface as described above. For example, the end surface rises substantially perpendicularly from the base end position (see the ridge portion 11 shown in FIG. 4B). You may make it have.
The ridge portion 11 of the present embodiment is a base end portion on the intake port 2 side provided at the position of the inner peripheral surface of the casing 10 within a range facing the outer end surface of the blade 42 (the inclined surface on the intake port 2 side). Or the said end surface) is continuously provided from the end surface by the side of the exhaust port 3 of the casing 10. FIG. With such a protrusion 11, the air that has been blown by the blades 42 does not lose the guide of the protrusion 11 on the way to the exhaust 3, and the protrusion 11 reaches the end face of the exhaust 3. Since the air is rectified and guided and discharged from the exhaust port 3, the exhaust air discharged from the exhaust port 3 has higher straightness.

  The ridge 11 may be provided in parallel to the uniaxial direction, but when viewed from the radial direction, it moves with an inclination (see θ in FIG. 2) in the rotational direction of the blade 42 toward the exhaust port 3 side. Preferably it extends. More specifically, as shown in FIG. 2, the end on the exhaust port 3 side of the ridge 11 is on the downstream side in the rotation direction of the blade 42 with respect to the proximal end of the ridge 11 on the intake port 2 side. It is located, and it is extended so that the direction where the protrusion part 11 extends may move to the rotation direction of the blade | wing 42. FIG.

  When the ridge portion 11 is extended so as to move in the rotation direction of the blade 42 in this way, the air subjected to the air blowing action of the blade 42 smoothly moves along the rotation direction of the blade 42 in the ridge portion 11. This is because the rectification is performed while being guided, so that the collision of the airflow with the ridge 11 that disturbs the air flow does not occur, and the generation of turbulence is suppressed.

  As shown in FIG. 1A, the protruding portion 11 has a protruding amount (based on the inner peripheral surface of the casing 10) toward the intake port 2 side at the base end of the casing 10 on the intake port 2 side. It is preferable that the inclined surface 12 has a gradient that decreases. In other words, it is preferable that the base 10 on the inlet port 2 side of the casing 10 is inclined so that the protruding amount becomes smaller toward the inlet port 2 side. If the inclined surface 12 at the base end of the ridge 11 is a vertical surface orthogonal to the air flow, the vertical surface and the airflow may collide with each other, and turbulence may occur. On the other hand, as shown in FIG. 1A, by using the inclined surface 12 having a gradient along the air flow, the collision between the vertical surface and the air flow that can occur in the case of the above-described vertical surface is achieved. It is avoided and generation of turbulent flow can be suppressed. In addition, in this embodiment, although the cross-sectional shape of the protrusion part 11 is made into the triangle, cross-sectional shape is not limited to this, For example, a kamaboko type | mold (semicircle, semi-elliptical shape) or a rectangle (rectangle, square, trapezoid) And so on.

(Impeller of the embodiment)
FIG. 3 is a rear view showing the impeller of the axial-flow fan according to the embodiment of the present invention.
As shown in FIG. 3, the blade | wing 42 has the step part 43 in an outer side end surface. As shown in FIG. 1A, the stepped portion 43 is formed so as to face the starting position of the ridge portion 11 on the intake port 2 side (the base end portion of the ridge portion 11 on the intake port 2 side). ing.

  Here, FIG. 4A is a partial cross-sectional view schematically showing the relationship between the protrusion 11 and the shape of the impeller. The arrows in the figure indicate the direction of air flow. As shown in FIG. 4A, the step 43 formed on the outer end surface of the blade 42 forms a gap between the protrusion 11 and the outer end surface of the blade 42 and the outer end surface of the blade 42 and the protrusion 11. The gaps between the portions of the casing 10 that are not formed and the inner peripheral surface of the casing 10 are formed to be substantially equal. That is, the protrusion amount of the ridge portion 11 with respect to the casing 10 is b, the gap between the ridge portion 11 and the outer end surface of the blade 42 is c, and the outer end surface of the blade 42 and the ridge portion 11 are not formed. When a gap between the partial casing 10 and the inner peripheral surface is defined as a, a and c are substantially equal. In this case, the gap between the base end portion (inclined surface) of the ridge portion 11 and the step portion 43 of the blade 42 is also a value approximate to a or c.

  Thus, by making the shape of the blade | wing 42 into the shape which has the step part 43, the clearance gap between the part of the outer side end surface of the blade | wing 42 which opposes the protrusion part 11, and the protrusion part 11, and the protrusion part 11 are made. Therefore, the gap between the outer end surface portion of the blade 42 that does not face the protruding portion 11 (that is, faces the inner peripheral surface of the casing 10) and the inner peripheral surface of the casing 10 is made substantially equal. be able to. More specifically, such a stepped portion 43 is formed as follows. In FIG. 4A, the alternate long and short dash line on the upper side of the drawing indicates the rotation center axis of the impeller 40. As shown in FIG. 4A, the stepped portion 43 is determined from the distance from the rotation center axis of the impeller 40 to the outer end surface (the outer end surface on the left side of the stepped portion 43 in the figure) at the portion facing the protruding portion 11. Also, the distance from the central axis of rotation of the impeller 40 to the outer end surface (the outer end surface on the right side of the stepped portion 43 in the drawing) of the portion that does not face the protruding portion 11 is increased. Here, as a matter of course, the outer end surface of the portion that does not face the protruding portion 11 faces the inner peripheral surface of the casing 10.

  Assuming that the outer diameter of the blade 42 is adjusted to the inner opening size of the casing 10 where the ridge 11 is formed, in the portion where the ridge 11 is not provided, the casing 10 A gap between the blades 42 becomes large. However, as described above, the stepped portion 43 is provided on the outer end surface of the blade 42 as described above, and the outer diameter of the blade 42 is changed between the portion with the protrusion 11 and the portion without the protrusion 11. In addition, it is possible to avoid an increase in the gap between the casing 10 and the blades 42 at a portion where the protruding portion 11 is not present.

  As a result, while the protrusions 11 are provided on the inner peripheral surface of the casing 10, the enlargement of the gap between the casing 10 and the blades 42 in the portion where the protrusions 11 are not present is avoided, and the static due to the enlargement of the gap is avoided. A decrease in pressure can be suppressed.

(Simulation and actual measurement data)
5A and 5B are diagrams showing the state of the exhaust air discharged from the exhaust port of the axial blower according to the embodiment of the present invention. FIG. 5A is a simulation result, and FIG. 5B is actual measurement data.
As shown in FIG. 5, according to the axial flow fan 1 of the present embodiment, the exhaust air discharged from the exhaust port 3 exhibits good straightness as compared with the conventional example shown in FIG. 6. The reason is that the casing 10 of the axial blower 1 according to the embodiment of the present invention has a plurality of protrusions 11 extending toward the exhaust port 3 on the inner peripheral surface facing the outer end surface of the blade 42. Since these ridges 11 rectify the airflow flowing along the inner peripheral surface of the casing 10 toward the exhaust port 3, the exhaust air discharged from the exhaust port 3 is difficult to spread and has high straightness. It is thought that it is discharged in an air current state.

  As described above, according to the axial blower 1 that is excellent in the straightness of the exhaust air, the exhaust air can be efficiently applied to the object. Therefore, when used as a cooling fan, a good cooling effect can be obtained. For example, it can be suitably used for a server that uses a plurality of blowers side by side as a cooling device.

(Effect of embodiment)
The operational effects of the axial fan 1 described above will be described.
According to the axial blower 1 of the present embodiment, the casing 10 having the intake port 2 and the exhaust port 3 in the uniaxial direction and the plurality of blades 42 on the outer peripheral portion of the hub 41 so that the hub 41 is along the uniaxial direction. Since the casing 10 has a plurality of ridges 11 extending toward the exhaust port 3 on the inner peripheral surface facing the outer end surface of the blade 42, the impeller 40 disposed in the casing 10 is provided. The straightening performance of the exhaust air can be improved by suppressing the generation of turbulence while avoiding an increase in noise and a decrease in static pressure by the rectifying action of the protrusions 11.

Moreover, since the blade | wing 42 has the step part 43 in an outer side end surface, as shown to Fig.4 (a), the clearance gap between the protrusion part 11 and the blade | wing 42 in the part in which the protrusion part 11 was provided (FIG. And the gap between the casing 10 and the blade 42 (shown by the reference symbol a in the figure) in the portion where the protruding portion 11 is not provided, and as a result, the inner peripheral surface of the casing 10 Although the protrusions 11 are provided on the upper surface, it is possible to avoid an increase in the gap between the casing 10 and the blades 42 and suppress a decrease in static pressure due to the increase in the gap.
Incidentally, FIG. 4B is a diagram drawn in association with FIG. 4A, and is a diagram in the case where the outer end face of the blade 42 does not have a stepped portion (corresponding to reference numeral 43 in FIG. 4A). It is. As shown in FIG.4 (b), in the part which does not have the protrusion part 11 with respect to the clearance gap (it shows with the code | symbol d in the figure) between the protrusion part 11 and the blade | wing 42 in the part in which the protrusion part 11 was provided. It can be seen that the gap between the casing 10 and the blades 42 (indicated by symbol e in the figure) becomes large. In this case, the large gap e may cause a decrease in static pressure.

  In addition, since the protrusion 11 is provided continuously from the position in the range facing the outer end surface of the blade 42 to the end surface on the exhaust port 3 side of the casing 10, it receives the air blowing action of the blade 42. The air is guided to the end surface of the exhaust port 3 while being rectified to the end portion 11 without being lost on the way to the exhaust port 3 and discharged from the exhaust port 3. Therefore, it is possible to discharge exhaust air having high straightness from the exhaust port 3.

  Further, since the protrusion 11 extends so as to move in the rotation direction of the blade 42 toward the exhaust port 3 when viewed from the radial direction, the air subjected to the air blowing action of the blade 42 is changed to the blade 42. It is rectified while being smoothly guided by the protrusion 11 so as to follow the rotation direction. Therefore, the collision between the ridge 11 and the air flow that disturb the air flow does not occur, and the occurrence of turbulence is suppressed.

  Further, the ridge 11 has an inclination with a gradient such that the protruding amount (based on the inner peripheral surface of the casing 10) becomes smaller toward the intake port 2 side at the base end portion of the casing 10 on the intake port 2 side. Since the surface 12, that is, the inclined surface 12 that follows the air flow, the airflow is not disturbed by the inclined surface 12, and the generation of turbulent flow is suppressed.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 1 Axial flow fan 2 Intake port 3 Exhaust port 10 Casing 11 Projection part 12 Inclined surface 13 Bearing housing 13a Bearing 20 Base part 30 Stator blade 40 Impeller 41 Hub 42 Blade 43 Step part 44 Shaft 50 Stator 51 Stator core 52 Insulator 53 Coil 60 Rotor 61 Rotor yoke 62 Rotor magnet 70 Motor part

Claims (3)

An axial blower,
A casing having an inlet and an outlet in a uniaxial direction;
A plurality of blades on the outer periphery of the hub, and an impeller disposed in the casing so that the hub is along the uniaxial direction.
The casing, on the inner peripheral surface facing the outer end surface of the blade, have a plurality of protrusions extending toward the exhaust port side,
The blade has a stepped portion on the outer end surface facing the proximal end portion of the protruding portion,
The step portion has a distance from the rotation center axis of the impeller to the outer end surface that does not face the ridge portion, rather than a distance from the rotation center axis of the impeller to the outer end surface that faces the ridge portion. Is formed by being lengthened,
The base end portion of the ridge portion on the intake port side is located at the position of the inner peripheral surface of the casing within a range facing the outer end surface of the blade, and the ridge portion extends from the base end portion of the casing. axial blower characterized that you have provided continuously to the end surface of the exhaust port side. 2. The axial flow fan according to claim 1, wherein the protruding portion extends so as to move in the rotation direction of the blade as it goes toward the exhaust port when viewed from a radial direction. The protruding portion is inclined so that a protruding amount from an inner peripheral surface of the casing becomes smaller toward a side of the intake port at a base end portion of the casing on the intake port side. The axial blower of Claim 1 or Claim 2 .